Direct endoscopic lavage and biopsy sampling and evaluation of uterine microflora in various stages of the canine estrous cycle

The microbial population of the uterus fluctuates during the estrous cycle. Microflora of uterus may affect the establishment and maintenance of pregnancy in bitches. The endoscopic samples obtained from the vagina and uterus of 20 female adult mixed‑breed dogs. The uterine lavage samples were prepared for cytology, bacterial (aerobic and anaerobic) and fungal cultures. Uterine tissue samples were evaluated for the presence of E. coli by the polymerase chain reaction. The pure growth of bacteria was observed in seven plates out of the nineteen cultured samples (36.84%) and five Gram-negative and two Gram-positive bacteria were detected. The highest number of isolated bacteria was related to the samples of the diestrus and anestrus stages of the estrous cycle, while the lowest number of bacteria was observed in the samples of the estrous stage. Moreover, Citrobacter spp. was the most frequent group of isolated bacteria. The neutrophils were detected in the cytology of uterine samples. The fungi growth was observed in three uterine samples. Cladosporium and Penicillium isolated from the samples were related to the estrus stage, and yeast was grown in diestrus samples. 16srRNA gene existed in all of the estrous uterine samples in which the bacterial culture was negative. However, the presence of this gene was proven in two samples (33.30%) of negative bacterial culture samples from the diestrus and anestrus stages. In conclusion, the normal bitches’ uteri were infected with various bacteria in estrus, diestrus and anestrus stages of the estrous cycle, and it could coincide with the fungi infection.